WW2010
University of Illinois

WW2010
 
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> online guides
 
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Online Guides
 
  introduction
 
> meteorology
 
  remote sensing
 
  reading maps
 
  projects, activities

Meteorology
 
  introduction
 
  air masses, fronts
 
> clouds, precipitation
 
  el nino
 
  forces, winds
 
  hurricanes
 
  hydrologic cycle
 
  light, optics
 
  midlatitude cyclones
 
  severe storms
 
  weather forecasting

Clouds, Precipitation
 
  introduction
 
> development
 
  cloud types
 
  precipitation

Development
 
  states of water
 
  relative humidity
 
  rising air
 
  convection
 
  convergence
 
  topography
 
> fronts
 
  rain or snow

User Interface
 
  graphics
> text

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Lifting Along Frontal Boundaries
when air masses interact

Lifting also occurs along frontal boundaries, which separate air masses of different density.

[Image: precip development along a cold front (27K)]

In the case of a cold front, a colder, denser air mass lifts the warm, moist air ahead of it. As the air rises, it cools and its moisture condenses to produce clouds and precipitation. Due to the steep slope of a cold front, vigorous rising motion is often produced, leading to the development of showers and occasionally severe thunderstorms.

[Image: precip development along a warm front (23K)]

In the case of a warm front, the warm, less dense air rises up and over the colder air ahead of the front. Again, the air cools as it rises and its moisture condenses to produce clouds and precipitation. Warm fronts have a gentler slope and generally move more slowly than cold fronts, so the rising motion along warm fronts is much more gradual. Precipitation that develops in advance of a surface warm front is typically steady and more widespread than precipitation associated with a cold front.



topography
Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

rain or snow